This is a renewal application for a Midcareer Investigator Award in Patient-Oriented Research (K24). The applicant, Dr. Garry Gold, is a physician-scientist, Professor of Radiology, Bioengineering, and Orthopedics at Stanford University. Over the past 15 years, Dr. Gold has developed expertise in several advanced musculoskeletal imaging and biomechanics techniques and applied these to the study of osteoarthritis and joint diseases. This has led to his developing an independent patient-oriented research (POR) career. He has received two independent research awards from the NIH that use MR techniques to investigate the pathophysiology of musculoskeletal diseases (both from NIBIB) and recently received an award from NIAMS to use Weight-Bearing CT to study joint loading. Dr. Gold has a 10-year history of mentoring junior clinician scientists, postdoctoral fellows, medical students, graduate students, and undergraduates - all performing POR. In addition, Dr. Gold has active collaborations with many NIH-funded investigators in the area of musculoskeletal research and imaging. The current application requests funding (50% salary) for 5 years. This funding will guarantee that the candidate will have at least 70% protected time to conduct his ongoing research and to continue to mentor clinician scientists performing POR. This award will free time now devoted to administrative and clinical responsibilities to focus more on his research and mentoring activities over the next 5 years. In addition to working on the ongoing NIH-funded projects, Dr. Gold will obtain additional training in advanced MR collection and analysis methods. This will allow the candidate to develop new approaches to apply to the imaging of musculoskeletal diseases. Given the outstanding resources and collaborations at Stanford, these novel projects are expected to be either renewed or to lead to new directions in orthopedic research, and significantly contribute to our scientific understanding of these disabling conditions.